机构地区: 西安交通大学能源与动力工程学院动力工程多相流国家重点实验室
出 处: 《内燃机学报》 2010年第5期399-406,共8页
摘 要: 在一台天然气/氢气混合燃料火花点火式发动机上,开展了不同掺氢比和不同废气再循环(EGR)率下发动机的燃烧特性研究。研究结果表明:掺氢比一定时,火焰发展期、快速燃烧期和燃烧持续期均随EGR率的增加而增加;EGR率一定时,火焰发展期、快速燃烧期和燃烧持续期均随掺氢比的增加而缩短,氢气的加入对火焰发展期的改善作用比对快速燃烧期的改善作用更明显。掺氢比的增加可降低平均指示压力的循环变动系数,相同平均指示压力循环变动系数下掺氢可允许使用更大的EGR率,大EGR率时天然气掺氢对平均指示压力循环变动系数的降低效果更为明显。 An experimental study on the effect of hydrogen fraction and EGR rate on combustion charac- teristics of a spark-ignition engine fuelled with natural gas-hydrogen blends was conducted. The results showthat, for a specified hydrogen fraction, the flame development duration, the rapid combustion dura- tion and the total combustion duration are increased with the increase of EGR rate. At a given EGR rate, the flame development duration, the rapid combustion duration and the total combustion duration are de- creased with the increase of hydrogen fraction in the blends. Hydrogen addition gives the larger influence on the flame development duration than the rapid combustion duration. Hydrogen addition into natural gas decreases the coefficient of variation of the indicated mean effective pressure and the effectiveness becomes more obviously at high EGR rate.
关 键 词: 火花点火发动机 天然气 氢气 废气再循环 燃烧特性
领 域: [动力工程及工程热物理]